SENSITIZATION INTERVAL AND ADMINISTRATION METHOD ALTER THE EFFECT OF 15-DEOXYSPERGUALIN ON HEART-TRANSPLANTATION IN SENSITIZED RECIPIENT RATS

We evaluated the effect of 15-deoxyspergualin (DSG) on accelerated rej ection. Brown Norway rats (BN) served as organ donors and Lewis rats ( LEW) as recipients. In an accelerated rejection model, after a LEW rat was sensitized with BN skin, a BN heart was transplanted. Various int ervals between sensitization and heart transplantation were examined. The heart allografts in sensitized recipients were rejected earlier th an those in unmodified recipients regardless of the sensitization inte rval. DSG (2.5 mg/kg per day), given to the recipients during the sens itization phase, significantly prolonged graft survival compared with the untreated hosts when the sensitization interval was short. When th e recipients were treated with DSG after heart transplantation, heart graft survival was significantly prolonged regardless of the sensitiza tion interval. Flow cytometric analysis and complement-dependent cytot oxicity tests revealed that DSG suppressed antidonor antibody formatio n and that postoperative administration of DSG significantly decreased the proliferation of B cells when the sensitization interval was shor t and the proliferation of class II antigen-positive cells when the se nsitization interval was long.